One thing I found installing 2.6:
I installed the test blog in a secured (SSL) environment, so my access would be https://my_web/blog.
No way. At least: index.php IS accessed but no stylesheet is accessed, not is any content. Login failes: cannot find page; admin acess fails, cannot find page.
The reason is that in the options table, the records for "Site URL" and "HOME" lines state "http://my_web/blog" where it _should_ read "https://my_web/blog". After changing this, it worked fine.
Would it be an idea that if a new blog is created, to use the same protocol here that is used creating the blog (so "http" is the install script is run using a non-SSL link, and "https" if SSL is used)?
(I propabvly had the same issue on previous versions)